This invention relates to ultrasonic surgical systems and, more particularly, to a customized hand piece connector for providing an electrical connection between a surgical instrument hand piece and a power source, e.g., a generator, for delivering power to the hand piece.
It is known that electric scalpels and lasers can be used as a surgical instrument to perform the dual function of simultaneously effecting the incision and hemostatis of soft tissue by cauterizing tissues and blood vessels. However, such instruments employ very high temperatures to achieve coagulation, causing vaporization and fumes as well as splattering, which increases the risk of spreading infectious diseases to operating room personnel. Additionally, the use of such instruments often results in relatively wide zones of thermal tissue damage. Thus, it is preferable to use instruments which do not have these associated disadvantages.
Cutting and cauterizing of tissue by means of surgical blades vibrated at high speeds by ultrasonic drive mechanisms is also well known. One component of this type of system is an ultrasonic generator which produces an electrical signal of a particular voltage, current and frequency. The generator is connected by a cable to a hand piece, which contains piezoceramic elements forming an ultrasonic transducer. In response to a switch on the hand piece or a foot switch connected to the generator by another cable, the generator signal is applied to the transducer, which causes a longitudinal vibration of its elements. A structure connects the transducer to a surgical blade, which is thus vibrated at ultrasonic frequencies when the generator signal is applied to the transducer. The structure is designed to resonate at the selected frequency, thus amplifying the motion initiated by the transducer.
A connector assembly serves to electrically connect the hand piece to the generator for powering the transducer in the hand piece and causing the necessary mechanical vibrations. Typically, the connector which is used is of a general construction and thus a number of hand pieces from a number of manufacturers may be mated with one specific generator of a preferred type. The connector will often include a number of electrical pins which provide an electrical connection between the hand piece and a mating electrical receptacle provided in the generator. The electrical pins are arranged in various patterns depending upon the application and very often the electrical pins have small diameters and thus are relatively fragile in nature. If a user attempts to insert the connector into the mating receptacle of the generator without having the conductive pins and ports of the mating receptacle properly aligned, the electrical pins will be bent and damaged.
Most types of medical connectors and the respective mating receptacle each have two sets of electrical pins which have two different functions. Each includes a non-isolated set of contacts (pins/contacts) which are referenced to ground and a patient set of contacts (pins/receptacles). The set of contacts for each group are physically and electrically isolated from the other group by a separator member. This separation provides electrical safety. However, effective electrical separation is not achieved if the connector is not properly seated within the receptacle.
Thus, there is a need to produce a connector which is designed to limit the mating capabilities between the generator and hand piece so that only a hand piece of a preferred type may be properly aligned and mated with the generator so as to ensure optimum performance and results.
The present invention is directed to a customized connector assembly for providing a secure electrical connection between a surgical hand piece and a power source, e.g., a generator. Preferably, the surgical hand piece comprises an ultrasonic cutting instrument for facilitating the performance of surgical procedures, such as simultaneous soft tissue dissection and cauterization of large and small blood vessels through the use of a precisely controlled ultrasonically vibrating blade or scalpel. The generator is of an ultrasonic type and is designed to produce an electrical signal of a particular voltage, current and frequency. The electrical (generator) signal is applied to a transducer disposed within the hand piece and longitudinally vibration of the elements of the hand piece is effectuated. More specifically, the transducer is connected to the surgical blade by a member so that the surgical blade will therefore be vibrated at ultrasonic frequencies when the generator signal is applied to the transducer. The structure is designed to resonate at the selected frequency, thus amplifying the motion initiated by the transducer.
The connector assembly of the present invention includes a first member which is connected at one end of the cable opposite to the hand piece. The first member comprises a partially hollow member for routing wires of the cable through the first member and into the connector once the connector is sealingly coupled to the first member. The first member has a number of features which permit the user to easily grip the first member. At one end thereof, the first member has a resilient skirt with a cavity formed therein. The cavity is designed to receive a second end of the connector. The resilient skirt is disposed about the connector in a sealing manner so as to shield the electrical wires of the cable.
The first member also includes a resilient arm extending therefrom which connects the first member to an end cap member. The resilient nature of the arm permits the arm to be manipulated and bent to permit the end cap member to be aligned and inserted within a first end of the connector. The end cap member is contoured at one end for the user to grip and at an opposite end, the end cap member has a resilient flange. The resilient flange is sized to be received within a cavity formed at the first end of the connector to ensure that a compressed seal is provided when the end cap member is inserted into the connector. This seal is an optional feature which is attractive because surgical instruments, including the cable and connector assembly of the present invention, are typically subjected to post surgical cleaning processes in which a cleaning solution is used to bath the instruments. This cleaning solution is often corrosive and can damage internal components contained within the connector if continued exposure results. Advantageously, the first member along with the resilient arm and the end cap member are all integrally formed relative to one another and are preferably formed of suitable plastics materials which provide the desired resiliency and strength required for the normal use thereof.
The connector preferably comprises a rigid plastics member which receives electrical cable wires at the first end. The connector has an outer shell and includes an interior wall disposed within the connector. The interior wall extends between the outer shell and is designed to partition the interior of the connector into first and second cavities with the first cavity being at the first end and the second cavity being at the second end. Preferably, the interior wall traverses the outer shell so that it is substantially perpendicular to an inner surface of the outer shell. The interior wall has a plurality of first openings formed therethrough which receive first electrical conductors (first pins) and a plurality of second openings formed therethrough for receiving second electrical conductors (second pins). The precise number and arrangement of the first and second openings will vary depending upon the specific application. The electrical conductors have a length such that a portion of each conductor extends into the first and second cavities.
According to one aspect of the present invention, the connector includes an isolation barrier which is preferably integrally formed with the other portions of the connector. The isolation barrier comprises a member formed on both surfaces of the interior wall so that a first section of the isolation barrier is disposed within the first cavity and extends towards the first end. A second section of the isolation barrier is disposed within the second cavity and extends towards the second end of the connector. Preferably, the isolation barrier is substantially perpendicular to the interior wall. The isolation barrier provides an insulative wall between the first and second electrical circuits housed within the connector. More specifically, the isolation barrier extends between the outer shell of the connector and serves to separate the first conductive pins from the second conductive pins. In the second cavity, the first and second conductive pins are typically electrically connected to other electrical devices, e.g., an EEPROM, and thus the isolation barrier is designed to separate these electrical devices from one another.
In another aspect of the present invention, the connector includes a keying feature formed in the outer surface of the connector. The keying feature comprises an elongated planar indentation formed in the outer surface of the connector. The keying feature orients the connector so it can be electrically plugged into the mating receptacle in only one way. This ensures that the first and second conductive pins are properly mated with matching receptacle electrical ports. This eliminates the risk that the connector will be incorrectly and forcibly mated with the generator resulting in the conductive pins being damaged, i.e. bent. The isolation barrier also provides a unique keying function as the mating receptacle must accommodate the isolation barrier when the connector is plugged therein. In the other words, the mating receptacle must have a slot or the like formed therein to receive the isolation barrier.
In yet another aspect of the present invention, the present connector provides improved separation between the non-isolated set of contacts (pin/receptacles) and the isolated set of contacts (pins/receptacles). In one embodiment this is provided for by reducing the lengths of one set of the electrical pins; namely, the non-isolated pins are preferably recessed deeper in the connector so that the isolated pins mate first with the corresponding isolated receptacles. Due to the electrical configuration of the connector, electrical power is not provided to the hand piece until the non-isolated pins mate with corresponding non-isolated receptacles. This requires the connector to be further disposed within the receptacle and thus ensures that a proper electrical connection is made therebetween.
The connector of the present invention permits easy and convenient mating between the preferred surgical cutting instrument and the accompanying preferred generator which was designed to be used with such preferred surgical cutting instrument. This ensures that the generator will be used with the hand piece which was designed to mate with it and thus a preferred mating arrangement results.